DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Information Disclosure Statement
The information disclosure statements (IDS) submitted on February 23, 2026 and June 5 2026, were filed after the mailing date of the Non-Final Rejection on January 20, 2026. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Response to Amendment and Status of Claims
Applicant’s amendments to the claims, filed March 12, 2026, are acknowledged. Claims 1, 3 and 4 are amended. Claims 5 and 6 are newly added. No new matter has been added.
Claims 1-6 are pending and currently considered.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-6 are rejected under 35 U.S.C. 103 as being unpatentable over Tomio (previously cited and cited by Applicant in IDS filed October 5, 2023, JP 2017031493 A, English Machine Translation provided).
Regarding Claim 1, Tomio discloses a stainless steel pipe (Abstract), having a chemical composition comprising, by mass%:
Element
Claim 1
Tomio (Abstract)
Overlap
C
0-0.05
0-0.06
0-0.05
Si
0-1.0
0-1.0
0-1.0
Mn
0.1-2.0
0.05-2.0
0.1-2.0
P
0-0.05
0-0.05
0-0.05
S
0-0.005
0-0.005
0-0.005
Cr
>16 to 20
15.5-18
>16-18
Mo
>0.6 to <1.4
1-3.5
1 to <1.4
Ni
3 to <5
2.5-7
3 to <5
Al
0.001-0.10
0.001-0.1
0.001-0.10
N
0.010-0.100
0-0.06
0.01-0.06
O
0-0.01
0-0.01
0-0.01
Cu
0.3-3.5
0.2-3.5
0.3-3.5
Balance
Fe + impurities
Fe + impurities
Fe + impurities
Tomio further satisfies the claimed relational expressions (1) and (2), wherein:
Cr+0.65*Ni+0.6*(Mo+0.5*W)+0.55*Cu-20*C ≥ 21.7 (1)
Cr+3.3*(Mo+0.5*W)-17*C ≥ 21.0 (2)
For example, the invention of Tomio includes a stainless steel pipe comprising 17% Cr, 4% Ni, 1.2% Mo, 1.5% W (see para. [0052] of Tomio), 2% Cu and 0.005% C, which equates to a value according to expression (1) of 21.8, which reads on the claimed greater than or equal to 21.7, and a value according to expression (2) of 23.4, which also reads on the claimed greater than or equal to 21.0.
Tomio further discloses:
a microstructure including, in terms of volume fraction, 10-55% ferrite, 0-15% retained austenite and a balance of tempered martensite, which reads on the claimed 20-40% ferrite, 5-25% retained austenite and 45% or more tempered martensite (para. [0081], martensite would be 30-90%, which reads on 45% or more; one of ordinary skill in the art would appreciate the martensite to be tempered martensite (not fresh martensite) – see para. [0065]), and
a yield strength of 758MPa or higher (para. [0080]), and
an absorbed energy at a temperature of -10C vE-10 of 80J or more, which reads on the claimed 40J or more (para. [0094]; see also Table 2 values; one of ordinary skill in the art would appreciate these values (inventive examples 1-2, 4-5, 10-11, 13-14, 16-17 and 19-20 which range from 145-178J, to be representative of the invention of Tomio).
Additionally, one of ordinary skill in the art would appreciate the invention of Tomio to comprise the claimed absorbed energy because the composition of Tomio (see above and Claim 2) is the same as claimed, and the method of Tomio (see Claims 3-4 below), is the same as claimed. When the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). See MPEP 2112.01.
Regarding the compositional and microstructural ranges, the yields strength, and the absorbed energy, in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP § 2144.05.I.
Regarding Claim 2, Tomio further discloses wherein the chemical composition further comprises, by mass%, at least one selected from group A to group E:
Group A
Tomio
citation
overlap
At least one of:
0-0.3% Ti
0-0.5% Nb
0-0.30% Nb
[0049]
0-0.3%
0-0.5% V
0-0.20% V
[0049]
0-0.20%
0-0.5% Ta
Group B
At least one of:
0-0.005% B
0-0.005% Ca
0-0.01% Ca
[0053]
0-0.005%
0-0.01% REM
0-0.1% REM
[0053]
0-0.01%
Group C
At least one of:
0-0.01% Mg
0-0.01% Mg
[0053]
0-0.01%
0-0.2% Zr
Group D
At least one of:
0-0.2% Sn
0-0.2% Sb
Group E
At least one of:
0-1.0% Co
0-3.0% W
0-3.0% W
[0052]
0-3.0%
In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP § 2144.05.I.
Regarding Claim 3 and Claim 4, Tomio discloses a method for manufacturing the steel pipe of Claim 1 (Abstract), the method comprising:
heating a steel pipe material to a heating temperature of 1150-1250C, which reads on the claimed range of 1100-1350C, performing hot working on the heated material to obtain a seamless steel pipe having a predetermined shape (para. [0035]; para. [0087], hot working at 850-1250C; para. [0059], heating to 1150-1250C; hollow shell reads on seamless pipe),
performing a quenching treatment of reheating the seamless pipe after the hot working to a temperature of 850-1050C, which reads on the claimed 850-1150C, and cooling to a stop temperature of 60C or lower, preferably 30C or lower, which reads on the claimed range of greater than 0C (see 112b rejection above) to 50C in terms of surface temperature, and cooling by water cooling, which reads on the claimed cooling rate equal to or higher than a cooling rate corresponding to natural cooling (para. [0063]-[0063]), and
performing a tempering treatment of heating the quenched steel pipe to a tempering temperature of 500-650C (para. [0065]).
Regarding Claim 5, Tomio is silent towards the claimed corrosion rate of 0.125 mm/y or lower.
Tomio teaches wherein Cr is included up to 18.0% in order to improve corrosion resistance against CO2 hot gas, and wherein if Cr content is too low, the effect cannot be obtained (para. [0041]).
Tomio also teaches including up to 3% W in order to increase stress corrosion cracking resistance in a high-temperature environment (para. [0052]).
Tomio further teaches wherein Cu is included up to 3.5% in order to increase the strength of the steel by age precipitation, whereby the effect is not obtained if the Cu content is too low (para. [0043]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included 18% Cr and 3% W, as taught by Tomio, in order to maximize corrosion resistance against CO2 hot gas, and in order to maximize stress corrosion cracking resistance in a high temperature environment (see teachings above). Further, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included 3.5% Cu as taught by Tomio, in order to maximize strength by precipitation hardening (see teachings above). One of ordinary skill in the art would further appreciate compositions of Tomio, which contain 18% Cr, 3% W and 3.5% Cu, satisfies the claimed requirements of equations (1) and (2) (equation (1) values range from 21.8 or more, which reads on the claimed 21.7 or greater, and equation (2) values range from 25.2 or more, which reads on the claimed 21.0 or greater).
The composition of Tomio as taught above and modified for improved corrosion resistance and precipitation strengthening is the same as the claimed composition (see Claim 1 and Claim 2 above) and comprises the same processing as claimed (see Claims 3-4 above). One of ordinary skill in the art would therefore appreciate that the invention of Tomio would comprise the claimed corrosion resistance rate, because the composition and processing of Tomio is the same as claimed. When the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). See MPEP 2112.01.
Regarding Claim 6, Tomio discloses a stainless steel pipe (Abstract), having a chemical composition comprising, by mass%:
Element
Claim 1
Tomio (Abstract)
Overlap
C
0-0.05
0-0.06
0-0.05
Si
0-1.0
0-1.0
0-1.0
Mn
0.1-2.0
0.05-2.0
0.1-2.0
P
0-0.05
0-0.05
0-0.05
S
0-0.005
0-0.005
0-0.005
Cr
>16 to 20
15.5-18
>16-18
Mo
>0.6 to <1.4
1-3.5
1 to <1.4
Ni
3 to <5
2.5-7
3 to <5
Al
0.001-0.10
0.001-0.1
0.001-0.10
N
0.010-0.100
0-0.06
0.01-0.06
O
0-0.01
0-0.01
0-0.01
Cu
0.3-3.5
0.2-3.5
0.3-3.5
Balance
Fe + impurities
Fe + impurities
Fe + impurities
Further, Tomio teaches wherein Cr is included up to 18.0% in order to improve corrosion resistance against CO2 hot gas, and wherein if Cr content is too low, the effect cannot be obtained (para. [0041]).
Tomio also teaches including up to 3% W in order to increase stress corrosion cracking resistance in a high-temperature environment (para. [0052]).
Tomio further teaches wherein Cu is included up to 3.5% in order to increase the strength of the steel by age precipitation, whereby the effect is not obtained if the Cu content is too low (para. [0043]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included 18% Cr and 3% W, as taught by Tomio, in order to maximize corrosion resistance against CO2 hot gas, and in order to maximize stress corrosion cracking resistance in a high temperature environment (see teachings above). Further, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included 3.5% Cu as taught by Tomio, in order to maximize strength by precipitation hardening (see teachings above).
One of ordinary skill in the art would further appreciate compositions of Tomio, which contain 18% Cr, 3% W and 3.5% Cu, satisfies the claimed requirements of equations (1) and (2) (equation (1) values range from 21.8 or more, which reads on the claimed 21.7 or greater, and equation (2) values range from 25.2 or more, which reads on the claimed 21.0 or greater).
Tomio further discloses:
a microstructure including, in terms of volume fraction, 10-55% ferrite, 0-15% retained austenite and a balance of tempered martensite, which reads on the claimed 20-40% ferrite, 5-25% retained austenite and 45% or more tempered martensite (para. [0081], martensite would be 30-90%, which reads on 45% or more; one of ordinary skill in the art would appreciate the martensite to be tempered martensite (not fresh martensite) – see para. [0065]), and
a yield strength of 758MPa or higher (para. [0080]), and
an absorbed energy at a temperature of -10C vE-10 of 80J or more, which reads on the claimed 40J or more (para. [0094]; see also Table 2 values; one of ordinary skill in the art would appreciate these values (inventive examples 1-2, 4-5, 10-11, 13-14, 16-17 and 19-20 which range from 145-178J, to be representative of the invention of Tomio).
Regarding the compositional and microstructural ranges, the yields strength, and the absorbed energy, in the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP § 2144.05.I.
Tomio is silent towards the claimed corrosion rate of 0.125 mm/y or lower.
However, the composition of Tomio as taught above and modified for improved corrosion resistance and precipitation strengthening is the same as the claimed composition, and Tomio comprises the same processing as claimed (see Claims 3-4 above). Therefore, one of ordinary skill in the art would appreciate that the invention of Tomio would comprise the claimed corrosion resistance rate, and claimed properties such as absorbed energy, because the composition and processing of Tomio is the same as claimed. When the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). See MPEP 2112.01.
Response to Arguments
Applicant's arguments filed May 12, 2026, regarding Claim 1, and dependent claims thereof, rejected under 35 U.S.C. 103 over Tomio, have been fully considered but they are not respectfully not found persuasive.
Applicant argues that Tomio fails to disclose the claimed relationships (1) and (2), and that the rejection relies on a randomly selected and undisclosed composition within Tomio’s broader ranges to read on the limitation.
Applicant argues that the examiner does not provide ranges to demonstrate an overlap with the claimed expressions.
This argument is not found persuasive.
The rejection demonstrates that the compositions of Tomio overlap the claimed expressions, and calculations using a composition representative of the invention of Tomio is sufficient to show the overlap. One of ordinary skill in the art could also easily calculate the full ranges and overlap of Tomio by considering the disclosed ranges for Cr, Ni, Mo, W, Cu and C used to calculate the value of expression (1), and of Cr, Mo, W and C, used to calculate the value of expression (2). One of ordinary skill in the art would therefore appreciate that the broader disclosure of Tomio comprises values ranging from 16.6-27.5 for expression (1) and 17.8-34.5 for expression (2), which further overlap the claimed ranges of 21.7 or greater and 21.0 or greater, respectively.
Applicant argues that there is criticality to the claimed expressions (1) and (2), and that steels which do not meet the criteria of expression (1) fail to comprise adequate corrosion resistance.
Applicant argues that steel Z fails to meet expression (1) and both corrosion tests, and that steel AD, while meeting the claimed expression (1), fails the corrosion test because Ni is 2.8% and below the claimed at least 3%.
Applicant argues that steel X and steel Y did not satisfy expression (2) and failed the SCC resistance test, and that steel AB, AC and AF, while satisfying expression (2), fail to meet Mo, Cu and W ranges.
These arguments are not found persuasive.
The steels referred to by Applicant are not commensurate in scope with the claims:
Steel Z – 15.8% Cr, claims require greater than 16% Cr
Steel AD – 2.8% Ni, claims require at least 3% Ni
Steel X – 0.1% Mo, claims require greater than 0.6% Mo
Steel Y – 0.058% C, claims require 0.05% or less
Steel AB – 1.7% Mo, claims require less than 1.4% Mo
Steel AC – 3.7% Cu, claims require at most 3.5%
Steel AF – 3.2% W, claims require at most 3% W when present (it is noted that W is currently an optional element – see Claim 1 and Claim 2).
Applicant therefore has not sufficient shown wherein steels which comprise compositions within the individually claimed elemental ranges, but fail to meet the claimed expressions (1) and/or (2), unexpectedly have poor corrosion resistance or SCC resistance.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Kimura (US 20060243354 A1): teaches wherein Cr+0.65Ni+0.6Mo+0.55Cu-20C ≥19.5, including values as high as 22.00, in order to secure sufficient corrosion resistance and rates within of 0.074-0.125 mm/y or less (Abstract; Fig. 3, Table 1 and 4, corrosion rates in Tables 2-3).
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CATHERINE P SMITH whose telephone number is (303)297-4428. The examiner can normally be reached Monday - Friday 9:00-4:00 MT.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Walker can be reached at (571)-272-3458. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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CATHERINE P. SMITH
Patent Examiner
Art Unit 1735
/CATHERINE P SMITH/ Examiner, Art Unit 1735
/KEITH WALKER/ Supervisory Patent Examiner, Art Unit 1735
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